What about Vitamin B12?

By Jane Birch 

Note: In 2019, it was discovered that B12 is found in at least some plant foods that are traditionally-common (even if we don’t eat them today). Check out this article on “water lentils.” I also highly recommend this video introduction to plant-based sources of B12. Mic the Vegan does a great job introducing water lentils (duckweed) and explaining why it is a natural source of B12. In addition, he reveals, it is not the only plant source of B12. He concludes, “Based on a lot of commonly-eaten plant foods [we thought] B12 wasn’t in plant foods at all, but the reality is we were just not looking. There are likely a lot of plants that were eaten throughout human history that had B12.” This rest of this FAQ below was written before this discovery. I find it interesting to realize how little we understand about how the world works and how quick we are to doubt God’s dietary counsel because of our lack of knowledge (e.g. so many people have thought that because there are no good plant-based sources of B12 that this way of eating is not God’s way. Turns out, there are plant-based sources!).

Vitamin B12 is produced by bacteria found mainly in dirt, untreated water sources, and the guts of some mammals. Most of us thoroughly wash all the dirt off of our vegetables and drink sanitized water, and so we don’t get the Vitamin B12 our ancestors got from eating plants or drinking from streams. Like some mammals, the human gut contains B12-synthesizing bacteria, but this is not known to be a reliable source of sufficient B12. Whole food, plant-based (WFPB) experts recommend taking a Vitamin B12 supplement if you do not consume any animal foods. Fortunately, in our day, this is extremely easy and inexpensive.

Some people are troubled by a diet that “lacks” an essential vitamin. I’m not one of them. In our day, we can easily include Vitamin B12 supplements as part of our diet, so to me the diet is not lacking. The fact is, many people who eat animal foods also lack B12 and need to supplement (The Institute of Medicine advises everyone over the age of 50 use B12 supplementation). Even animals grown for food can be B12 deficient and require B12 supplements or injections. Fortunately, people eating a WFPB diet that can easily get adequate B12 from supplements or fortified foods.

B12 is cheap, and you don’t need much. You can take a small amount of either cyanocobalamin or methylcobalamin every day (25 – 100 mcg) or take a larger amount (1000 mcg) once or twice a week. (To read the various recommendations made by experts, see: B12 Supplements.)

From more information: Dr. Sofia Pineda Ochoa, “Vitamin B12: All Your Questions Answered”; Dr. John McDougall, “Vitamin B12 Deficiency—the Meat-eaters’ Last Stand”; Dr. Michael Greger, “Safest Source of B12.”; Dr. Thomas Campbell, “12 Questions Answered Regarding Vitamin B12” and VeganHealth.org, “What Every Vegan Should Know about Vitamin B12.”

If a WFPB diet requires a supplement, how can it be correct?

Some people feel strongly that the Lord would not recommend a diet that requires a supplement or they feel that if a WFPB diet requires a supplement, it must not be correct. To me, a WFPB diet answers so many of the important questions about health and nutrition, I am untroubled if it leaves some smaller questions unanswered. The fact is, there are unanswered questions about everything important in life. Some people think The Church of Jesus Christ of Latter-day Saints can’t possible be true because of some historical fact that is not answered to their satisfaction. Claiming that a WFPB diet can’t be correct if it requires a supplement is like claiming the Book of Mormon can’t be true because it mentions horses and steel or saying Joseph Smith is a false prophet because he married a 14-year old (see note below). In these cases we are using our current very limited understanding of the world to discount the greater truths that have been given us.

We live by faith. We don’t have all the answers to every question, but we have enough answers to make all the important decisions. I like what BYU Professor Kerry Muhlestein said on this topic:

God’s ways of thinking are higher than ours, and thus we should not be surprised when we don’t understand everything he has said or done. I have spent my adult lifetime studying the translation of the Book of Abraham. Some have experienced a kind of crisis over what the world has to say about Joseph Smith’s abilities to translate and how it relates to the Book of Abraham. . . .  I can tell you that careful study and research has provided very strong and well supported answers for all of the major questions those in the great and spacious building have thrown at us. Note that I said all of the major questions, but I did not say every question. There are still questions about the translation of the Book of Abraham for which we have no answers. In fact I have sat down numerous times and tried to come up with hypotheses that could account for all the facts we have at our disposal. . . . but in truth, nothing I have thought of can account for all the data we have. And in some ways this is very comforting to me. . . . wouldn’t we be surprised if we could understand exactly how God works . . . Frankly, given my current limited and finite mind, I would be a bit disappointed if I was capable of understanding just how God works. (“Why We Must Be Wholeheartedly Holy,” BYU Devotional, May 12, 2015)

We don’t fully understand God’s work of creating our bodies and the nutrients we need. Many things we now think we understand will turn out to be incorrect. For example, we used to think plant proteins were “incomplete” and that we needed animal foods for adequate protein (or at least needed to combine various plant foods to create “complete proteins”). Some people discounted vegetarianism for this reason: Why would God want us to rely on incomplete proteins? Now, of course, we have learned that this understanding of protein is completely incorrect. Plant proteins are not “incomplete” and they are, in fact, healthier for our bodies than animal proteins. (See: Where Do You Get Your Protein?)

Of course, there is not just one diet that is compatible with the Word of Wisdom, but in my opinion, a WFPB diet is in harmony with Word of Wisdom and answers all of the major questions we have about nutrition and how to eat for optimal health. I am untroubled by minor questions that are not fully answered. I invite anyone to find a diet that is more in line with the Word of Wisdom, demonstrates just as good clinical results, and has a satisfactory answer for every questions that can be asked of it. Regardless, we each have the responsibility to study each topic and seek the Lord’s guidance about what we should do as individuals.

Why would a healthy diet require a supplement?

As I’ve stated, I’m not personally troubled by this questions, but here are some of my thoughts:

1. The science of nutrition is in its infancy. There are many things we don’t currently fully understand. One of these is Vitamin B12. There are many details we are lacking. It will take a lot more hard work to continue to uncover additional hidden treasures of knowledge as to the function of this nutrient, the ideal sources for it, and how much we actually need. Our best chance of discovering the hidden treasures of knowledge we lack is to cherish and fully live by the light we have received. As we do so, the Lord will give us more light and we will grow “brighter and brighter until the perfect day” (D&C 50:24). Just like with the idea of “incomplete” plant proteins, we’ll one day understand why this question about B12 is not a threat to the Word of Wisdom.

2. If we need to consume Vitamin B12, we can get it either from consuming animal foods or taking a supplement. When we use the supplement, we get what we need without anything dangerous being consumed with it. When we eat animal foods, along with the little bit of Vitamin B12 we need, we get a whole lot of stuff that is damaging to our bodies: animal protein, lots of fat, animal hormones, and all kinds of possible pollutants. To me, it is obvious which source is superior, and which might be more pleasing to the Lord.

3. We live in a fallen world. Many things are not ideal. Adam and Eve ate a totally plant-based diet in the Garden Eden and never needed B12 supplements. We have left the Garden, and we’ve since done a lot of damage to our DNA and to our physical and cultural environment. Through many generations of eating less than an ideal diet, it is possible our bodies became dependent on the B12 found in animals. Perhaps this changed either our bodies and/or our environment enough that we are now paying a price. Supplementation may be one price we need to pay for living in a fallen world, at least until we better understand this nutrient and learn to eat a healthier diet.

If Vitamin B12 is essential, why is it not mentioned in D&C 89?

D&C 89 does not contain an exhaustive list of everything we should and should not do for good health. There are many diet-related health topics not explicitly discussed in the Word of Wisdom. For example:

• breastfeeding babies
• dairy and eggs
• narcotics and other dangerous drugs
• use of prescription drugs
• use of high fat plant foods, including vegetable oils
• sunshine (Vitamin D)
• water
• avoiding contaminated foods (even fresh organic plant foods can contain poisonous contaminants)
• the vital importance of clean water (this one issue has perhaps caused more deaths than almost anything else)

The Lord declared that the Word of Wisdom is “adapted to the capacity of the weak and the weakest of all saints” (D&C 89:3). Clearly there is more wisdom beyond this revelation. I feel the Word of Wisdom gives us basic principles that help put is on the right path. As we master the basics, the Lord will reveal to us more, perhaps much more, to us as individuals through personal revelation. Some of that personal revelation will be the Spirit leading us or confirming the work of scientists and other dietary experts. The Lord expects us to use our brains as well as our hearts to figure out what is right. He does not command in all things (D&C 58:26).

Note: For an interesting example of dealing with facts that seem to contradict what we believe is true, see “Why Are Horses Mentioned in the Book of Mormon?” I also love what Hugh Nibley wrote in the preface to a book he wrote on the Book of Mormon:

We are not going to prove anything in this book. The evidence that will prove or disprove the Book of Mormon does not exist. When, indeed, is a thing proven? Only when an individual has accumulated in his own conscience enough observations, impressions, reasonings, and feelings to satisfy him personally that it is so. The same evidence which convinces one expert may leave another completely unsatisfied; the impressions that build up to definite proof are themselves nontransferable. All we can do is to talk about the material at hand, hoping that in the course of the discussion every participant will privately and inwardly form, reform, change, or abandon his opinions about it and thereby move in the direction of greater light and knowledge. (Since Cumorah, p. xiv)

Note also: The Mankai plant also contains bioactive B12 compounds and could potentially serve as a plant-based food source of vitamin B12.

See also: Discovering the Word of Wisdom: Surprising Insights from a Whole Food, Plant-based Perspective by Jane Birch

Last updated: November 29, 2023